Which concept is important for object-oriented programming?

Encapsulation is a fundamental concept in object-oriented programming (OOP). It refers to the bundling of data (attributes) and methods (functions or procedures) that operate on that data into a single unit, typically a class. This concept is crucial because it helps to restrict direct access to some of an object's components, which can prevent unintended interference and misuse of the internal mechanisms of that object. By encapsulating data, OOP promotes greater modularity and organization, allowing developers to change or enhance the internal workings of a class without affecting other parts of the program that rely on it.

Ultimately, encapsulation leads to a clearer structure in code, making it easier to maintain, as it separates the interface (what an object can do) from the implementation (how it accomplishes those tasks). This separation is central to the principles of abstraction and information hiding in OOP, which enhances code reliability and reusability.